Torsion bar operated venting unit



March 3, 1970 J. o. HAZEN 3,498,207

TORSION BAR OPERATED VENTING UNIT Filed March 28, 1968 INVENTOR.

JOHN C. HAZEN AGENT United States Patent Ofifice 3,498,207 Patented Mar. 3, 1970 TORSION BAR OPERATED VENTIN G UNIT John O. Hazen, Monaca, Pa., assignor to .H. H.

Robertson Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Mar. 28, 1968, Ser. No. 716,852 Int. Cl. F23] 17/02 US. CI. 9886 17 Claims ABSTRACT OF THE DISCLOSURE A venting unit of the type adapted to quickly release explosion pressures and/or heat and smoke from the interior of a building. The venting unit includes a curb defining at least one discharge opening, a releasably retained, pivotal damper or cover biased in an open position but which normally seals the discharge opening, and torsion bars for forcibly opening the damper. The torsion bars are mounted externally of the curb and do not obstruct the discharge opening.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to venting units of the type having a releasably retained, pivotal damper or a cover sealing a discharge opening, and more particularly to improved means for forcibly moving the pivotal damper to an open position wherein the discharge opening is unobstructed.

Description of the prior art damper release mechanisms and the rigid supporting structure are positioned within the discharge opening of the vent. Therefore, one serious disadvantage of such prior art venting units is that the discharge opening is obstructed by the presence of the damper retaining mechanisms.

SUMMARY OF THE INVENTION The principal object of this invention is to provide improved means for forcibly opening the damper of a venting unit.

Another object of this invention is to provide torsion bars for forcibly opening the damper, wherein the torsion bars are mounted externally of the venting unit and do not obstruct the discharge opening.

Still another object of the present invention is to provide a venting unit incorporating torsion bars, wherein the torsion bars serve (1) to forcibly open the damper, and (2) to pivotally support the damper.

The present invention is directed to venting units of the type capable of quickly releasing explosion pressures and/or smoke and heat from the interior of a building. The damper unit may be provided with an opaque cover. Alternatively, the damper unit may be provided with a transparent or translucent cover in which case the damper unit also serves as a skylight.

Venting units of the type contemplated by this invention comprise a curb which surrounds an opening in a roof of a building and which projects thereabove. The

\ curb has at least one discharge opening and includes opposite curb end walls, a curb front wall and a curb back wall. A damper or cover overlies the discharge opening and is disposed in sealed engagement with the periphery of the discharge opening. The damper is pivotally supported for movement between its normally engaged position and an open position wherein the discharge opening is unobstructed. The damper is releasably retained in sealed engagement with the periphery of the discharge opening by damper retaining means including a thermal responsive triggering mechanism. Damper actuating means is provided for forcibly moving the pivotal damper to the aforesaid open position in the event of a fire or an explosion within the building.

In accordance with the present invention, the actuating means comprises a pair of torsion bars having central segments, operating ends and fixed ends. The torsion bars are disposed externally of the discharge opening. Support means connected to the curb back wall support the central segments of the torsion bars. The fixed ends of the torsion bars are secured to the curb. The operating ends of the torsion bars are engaged with the damper and positioned to forcibly urge the damper toward the open position. The central segments of the torsion bars are subjected to torsional stress when the damper is in sealed engagement with the periphery of the discharge opening, and are subjected to reduced torsional stress when the damper is in the open position.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is an isometric view of a venting unit incorporating the damper actuating means of this invention;

FIGURE 2 is a side view, partly in cross-section, of the venting unit of FIGURE 1 further illustrating the damper actuating means;

FIGURE 3 is a cross-sectional view taken along the line 33 of FIGURE 1;

FIGURE 4 is a cross-sectional view taken along line 44 of FIGURE 1; and

FIGURES 5, 6 and 7 are isometric views, similar to FIGURE 1, illustrating alternative embodiments of the damper actuating means of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) Referring to FIGURES 1 and 2, there is shown a venting unit 10 mounted on a roof 12 of a building 14. The venting unit 10 comprises a curb 16; a pivotal damper or cover 18; damper retaining means 20 for releasably retaining the damper 18 in a closed position; thermal responsive triggering mechanism 22 for operating the damper retaining means 20; and damper actuating means 24 for forcibly moving the damper 18 to the open position indicated in dotted outline in FIGURE 2.

The curb 16 surrounds a roof opening 26 and provides at least one discharge opening 28 communicating with the roof opening 26. The curb 16 includes opposite curb end walls 30, a curb front wall 32, and a curb back wall 34.

The pivotal damper 18 comprises a peripheral frame 36 to which is secured a transparent or translucent sheet 38. The damper 18 is pivotally supported on pivot means 40 which Will be more fully described later in the specification.

A sealant strip 42 of compressible material is positioned at the top of the curb 16 and defines the periphery 44 of the discharge opening 28. The sealant strip 42 is compressed by the damper 18 (FIGURE 4) to provide an essentially weather tight seal between the curb 16 and the damper 18.

the

The damper retaining means may comprise any suitable release mechanism. The damper release mechanism 20 illustrated herein is similar to that release mechanism described and claimed in US. Patent 3,337,991 to which reference is hereby made. For the purposes of this invention and with reference to FIGURE 4, the damper release mechanism 20 comprises separable plates 46, 48 carried by a mounting angle 50, secured to the curb front Wall 32. A U-shaped keeper 52 is secured to and depends downwardly from the damper 18 into the space between the separable plates 46, 48. The plate 46 is rigidly afiixed to the mounting angle 50. The plate 48 is pivotal in a slot 54 provided in the mounting angle 50, toward and away from the plate 46. A spring 58 urges the plate 48 toward the stationary plate '46. The plate 48 is displaced away from the stationary plate 46 by the keeper 52 against the force of the spring 58 when the damper 18 is being closed. The plate 48 is then returned by the spring 58- to that position shown in FIGURE 4 to latch the damper 18 in the closed position. The plate 48 is provided with an angle member 60 which extends toward the plate 46 and over the keeper 52. The angle member 60 is yieldably secured to the plate 48 by spring 62. The spring 62 permits the angle member 60 to be displaced upwardly away from the plate 48 and release the keeper 52 when explosion pressures are directed against the damper 18.

Referring to FIGURES 3 and 4, a chain 64 has one end connected to the plate 48 of the release mechanism 20 and its opposite end connected, for example, to the curb back wall 34 (FIGURE 3). The chain 64 contains the thermal responsive release mechanism 22 which employs a fusible link 66 to maintain a spring 68 under tension. The fusible link 68 melts at a preselected elevated temperature, for example, 175 F. When the fusible link 66 melts, the spring 68 will contract and pull the chain 64 to separate the plates 46, 48 thereby releasing the keeper 52 and the damper 18 for movement to the open position.

Referring again to FIGURES 1 and 2, the damper actuating means 24 comprises a pair of torsion bars 70, 72 having central segments 74, 76, fixed ends 78, 80, and operating ends 82, 84, respectively. The fixed ends 78, 80 are secured to the opposite curb end walls 30 by means, such as brackets 86 (only one visible). The operating ends 82, 84 are disposed exteriorly of the ends of the damper 18 and are secured thereto by means, such as eyebolts 88. The central segments 74, 76 of the torsion bars 70, 72 criss-cross at locations intermediate of their ends and are connected to the curb back wall 34 by support means, such as spaced brackets 90. Those portions of the central segments 74, 76 passing through each of the brackets 90 are positioned substantially in a common plane.

The overall arrangement of the torsion bars is such that the fixed end 78 (80) of each of the torsion bars 70 (72) is positioned adjacent to the operating end 84 (82) of the other of the torsion bars 72 (70).

The pivot means 40 comprise angle members 92 which are spaced-apart and include arm segments 94 secured to the peripheral frame 36 of the damper 18 and right angle arm segments 96 through which pass the central segments 74, 76. As can best be seen in FIGURE 3, the arm segment 96 is provided with an opening 98 which is large enough to permit free rotation of the angle member 92 about the central segment 76.

When the damper 18 is closed, that is in sealed engagement with the periphery 44 of the discharge opening 28, the central segments 74, 76 of the torsion bars are subjected to torsional stress which urges the damper 18 toward the open position. When the damper retaining means 20 releases the damper 18, the torsional stress of the central segments 74, 76 forcibly moves the damper 18 to the open position shown in FIGURE 2. When the damper is in the open position, the central segments 74, 76 of the torsion bars 70, 72 are subjected to reduced torsional stress which maintains the damper 18 spaced from the discharge opening28.

Alternative embodiments of the present damper actuating means are illustrated in FIGURES '5, 6 and 7. Corresponding numerals will be employed to identify corresponding parts heretofore described.

Referring to FIGURE 5, there is illustrated damper actuating means 24a mounted externally of the curb 16 of the venting unit 10. The damper actuating means 24a includes torsion bars 70a, 72a having central segments 74a, 76a supported by the space brackets a connected to the curb back wall 34. The fixed ends 78a, 80a extend generally vertically and are fixed to the curb back wall 34 by spaced brackets 86a. The brackets 86a are positioned adjacent to corners 100 of the curb 16. The operating ends 82a, 84a are disposed interiorly of the peripheral frame 36. The operating ends 82a, 84a engage the damper 18 and are positioned to forcibly open the damper 18 when the damper retaining means (not shown) is activated. The damper 18 is pivotally supported directly on the central segments 74a, 74b by the pivot means 40a.

Referring to FIGURE 6, there is illustrated damper actuating means 24b mounted externally of the curb 16 of the venting unit 10. The damper actuating means 24b comprises a pair of torsion bars 70b, 72b positioned on opposite sides of a reference plane P passing normally through the curb back wall 34 between the end walls 30. The torsion bars 70b, 72b have fixed ends 78b, 80b disposed on opposite sides but adjacent to the reference plane P. The fixed ends 78b, 80b are secured to the curb back wall 34 by means, such as a common bracket 102. If desired, the fixed ends 78b, 8% may be connected by a connecting segment 104 shown in dotted outline, which passes through the reference plane P, whereby the torsion bars 70b, 72b comprise an integral unit. Support means, such as brackets 106, support the central segments 74b, 76b in coaxially aligned relation and generally parallel with the curb back wall 34. The operating ends 82b, 84b are disposed interiorly of the peripheral frame 36 of the damper '18 and are positioned to forcibly urge the damper 18 to the open position when the damper retaining means .(not visible) is atcivated. The damper 18 is pivotally supported directly on the central segments 74b, 76b by the pivot means 40b.

Referring to FIGURE 7, there is shown damper actuating means 240. mounted externally of the curb 16 of the venting unit 10. The damper actuating means 24c comprises a pair of torsion bars 700, 72c disposed on opposite sides of a reference plane P passing normally through the curb back wall 34 between the end walls 30. In this embodiment, the operating ends 820, 84c are positioned adjacent to but on opposite sides of the reference plane P. The operating ends 82c, 840 are secured to the damper 18 by means, such as the common bracket 102. Support means, such as a plurality of brackets 106, support the central segments 74c, 76c in a coaxially aligned relation and generally parallel with the curb back wall 34. The fixed ends 780, 80c extend generally vertically and are secured to the curb back wall 34 adjacent to the corners 100 by means, such as the brackets 86c. Alternatively, the fixed ends 78c, 800 may extend generally horizontally and be secured to the curb end walls 30 by the brackets 860, as shown in dotted outline in FIGURE 7. The damper 18 is pivotally supported directly on the central segments 74c, 76c by the pivot means 400. The operating ends82c, 840 may be connected by a connecting segment 104 shown in dotted outline in FIGURE 7, which passes through the reference plane P, whereby the pair of torsion bars 70c, 72c comprise an integral unit.

I claim:

1. A venting unit, comprising:

a curb surrounding an opening in a roof of a building and projecting thereabove, said curb having at least one discharge opening and including opposite curb end walls, a curb front wall and a curb back wall;

a damper overlying said discharge opening and disposed in sealed engagement with the periphery of said discharge opening;

means for pivotally supporting said damper for movement between its normally engaged position and an open position wherein said discharge opening is unobstructed by the said damper;

retaining means for releasably retaining said damper in sealed engagement with the periphery of said discharge opening;

a pair of torsion bars having central segments, operating ends and fixed ends;

means for securing said fixed ends of said torsion bars to said curb;

support means connected to said curb back wall for supporting said central segments of said bars;

said operating ends being engaged with said damper and positioned to forcibly move said damper to said open position;

said central segments of said torsion bars being subjected to torsional stress when said damper is in sealed engagement with the periphery of said discharge opening and being subjected to reduced torsional stress when said damper is in said open position; and

means responsive to abnormal temperatures and pressures within said building for releasing said retaining means, whereby said damper is automatically, forcibly and rapidly moved to said open position by said torsion bars.

2. The venting unit of claim 1 wherein said torsion bars are disposed entirely outside of said discharge openmg.

3. The venting unit of claim 1 wherein said operating ends of said torsion bars are disposed exteriorly of said damper, and including means for securing said operating ends to said damper.

4. The venting unit of claim 1 wherein said fixed ends are secured to said opposite curb end walls.

5. The venting unit of claim 1 wherein said fixed ends are secured to said curb back wall.

'6. The venting unit of claim 1 wherein said central segments of said torsion bars criss-cross in the region of said curb back wall; and the fixed end of each of said torsion bars is positioned adjacent to the operating end of the other said torsion bars.

7. The venting unit of claim 1 where said fixed ends of said torsion bars are secured to corners of said curb.

8. The venting unit of claim 1 wherein said torsion bars are positioned on opposite sides of a reference plane passing normally through said curb back wall between the said end walls.

9. The venting unit of claim 8 wherein said fixed ends of said torsion bars are positioned adjacent to said reference plane and are secured to said curb back wall.

10. The venting unit of claim 8 wherein said fixed ends of said torsion bars are remote from said reference plane and are secured to said curb back wall.

11. The venting unit of claim 8 wherein said fixed ends of said torsion bars are remote from said reference plane and are secured to said opposite curb end walls.

12. The venting unit of claim 8 wherein said central segments of said torsion bars are coaxially aligned and generally parallel with said curb back wall.

13. The venting unit of claim 8 wherein those ends of said torsion bars adjacent to said reference plane, are connected whereby said torsion bars comprise an integral unit.

14. The venting unit of claim 1 wherein said means for pivotally supporting said dampers comprises:

spaced brackets having corresponding ends secured to said damper and corresponding opposite ends pivotally connected to said central segments of said torsion bars.

15. The venting unit of claim 14 wherein said spaced brackets are pivotally connected to the said central segments at locations adjacent to the operating ends of said torsion bars.

16. The venting unit of claim 14 wherein said spaced brackets are pivotally connected to the said central segments at locations adjacent to the fixed ends of said torsion bars.

17. A venting unit, comprising:

A venting unit comprising:

a curb surrounding an opening in a roof of a building and projecting thereabove, said curb having at least one discharge opening and including opposite curb end walls, a curb front wall and a curb back wall;

a damper overlying said discharge opening and disposed in sealed engagement with the periphery of said discharge opening:

means for pivotally supporting said damper for movement between its normally engaged position and an open position wherein said discharge opening is unobstructed by the said damper;

means for releasably retaining said damper in sealed engagement with the periphery of said discharge opening;

a pair of torsion bars having central segments, operating ends and fixed ends;

means for securing the fixed ends of said torsion bars to said curb;

support means connected to said curb back wall for supporting said central segments of said torsion bar; and

said operating ends of said torsion bars being disposed beneath said damper and interiorly of the edges of said damper and positioned to forcibly urge said damper toward said open position;

said central segments of said torsion bars being subjected to torsional stress when said damper is in sealed engagement with the periphery of said discharge opening and being subjected to reduced torsional stress when said damper is in said open position.

References Cited UNITED STATES PATENTS 2,602,957 7/1952 Anderson 16--180 2,707,808 5/1955 Anderson 16-180 XR 2,916,763 12/1959 Wagner 16-180 3,061,871 11/1962 Swanson 16180 3,377,939 4/1968 Sailors 98l19 MEYER PERLIN, Primary Examiner US. Cl. X.R. 

